So, okay, bear with me.
The Last of Us Season 2, it's no longer Cordyceps, it's now Masospora, Cicadina has taken over,
and all remaining humans become infected with it, and are running around having a giant
orgy.
But, plot twist, no one has any genitals because they've fallen off, or any arses.
It's just...
It's a nightmare, that's what it is.
Hello and welcome to The Bisexual Biologist.
My name is Riley, your host of the show, and this is a podcast where we talk queerness,
nature, and everything in between.
Okay girlies, it's pride month, and to celebrate, cicadas are acting gay.
The recent super-emergence of periodical cicadas in their trillions across North America has
been dubbed cicada-geddon, the likes of which hasn't been seen in decades.
As the Great Southern Brood and the Northern Illinois Brood both reach their respective
13th and 17th years of life, triggering the grand emergence from the underground.
But there's a fatal twist, the majority of them will emerge infected by a fungal pathogen
that causes them to become extremely hypersexual, and even homosexual.
Let's jump into this gay version of a bug's life.
Okay, so before we dive into the main topic of this episode, the fatal infection of cicadas
by a fungal pathogen, let's do a little crash course on what a cicada is.
Because some of you may not know what a cicada is, you may never have seen one before, most
likely you would have heard one because they are extremely fucking loud.
If you have lived somewhere where they emerge in summertime, you will know that it is sometimes
impossible to exist.
I remember once going outside to my parents place on a summer evening, you know, I wanted
to have a nice relaxing night, sit outside, with a beer, just you know, enjoy the serenity of
nature.
The cicadas were so noisy, I could not sit outside for longer than a minute.
My ears were ringing, it was deafening.
So cicadas, we love you, but God you are noisy.
Okay, so what's a cicada?
You might be asking.
Cicadas are insects, so they are from the class Insecta, the family Cicadidae, and the
genus Magi cicada is who we are going to be talking about today.
So there are seven species within this genus, and they are all found only within the eastern
parts of northern America.
So when you think of a cicada, it's a pretty stock standard insect, so think six legs and
three body parts with a head, a thorax and an abdomen.
They have wings as well when they have emerged into their final adult form.
So this particular group of seven species, as I said, was found only in northern America,
and they're known as periodical cicadas, as all individuals in the local population are
developmentally synchronized to emerge as adults at the same time.
So in the northern hemisphere, this usually occurs in early May into June, and that's
what a brood is.
So earlier I said the Great Southern Brood and the Northern Illinois Brood.
So a brood is the year or group of cicadas that were all born at the same year, and they
all emerge at the same time, 13 to 17 years later.
So they have a very interesting life cycle where 99% of it is spent underground in a
juvenile state known as a nymph.
So in biology, a nymph is the juvenile form of invertebrates, particularly insects, which
undergo gradual metamorphosis.
Still got it.
Okay, so that's a nymph for you.
That's what that means.
So, okay, back to these cicadas.
So as I was saying, they spend 99% of their lives underground as juveniles as nymphs, and
they spend majority of it just below the surface feeding on the roots of trees.
So whilst living underground in this nymph form, cicadas will feed on the xylem fluids
from the roots of deciduous trees above them.
In the spring of their 13th or 17th year of living underground, this particular genus
of cicadas, Magi cicada, the brood of nymphs will emerge at the same time and in tremendous
numbers.
So when early May arrives in the Northern Hemisphere, the nymphs collectively build
exit tunnels and a mass exodus to the world above occurs.
This can sometimes happen overnight, with all brood members crawling free by sunrise.
And this can times often be like billions or trillions of cicadas.
So they're like everywhere, like all over the forest floor.
Lots of bugs, lots of bugs.
From this point on, they will then attach themselves to the bark of a nearby tree and
undergo one final body transformation, which is molting their exoskeleton to reveal their
beautiful winged adult bodies.
In bugs life, when the beautiful caterpillar goes through his metamorphosis and comes out
as a beautiful butterfly with the tiniest little wings ever.
It's quite funny.
Back to cicadas and some fun facts.
So these Magi cicada species, the winged adults have two red compound eyes, a black dorsal
thorax, translucent wings with orange veins.
Sexy.
The abdomen may be orange, black or striped with orange and black.
Okay, so they can be orange on the under side, black on the under side, or they can have
a stripe of orange or black.
And they range from sizes from 2.4 to 3.3 centimetres.
So they're a little bit smaller than cicadas in Australia because the ones I am familiar
with here are much larger than that.
I would say they're like up to six centimetres for a big cicada.
And they're usually green, black or brown from memory.
The black ones used to be really rare.
Anyway, going off topic.
And a fun little fact, which I find quite interesting is that they are able to tell
how many years they've been underground because they can count.
So what these nymphs do, because they feed on the xylem, which is one of the tubules
of a plant, we have xylem and phloem.
Xylem is for water and minerals.
Phloem transports the nutrients or sugars that the plants make throughout the plant.
So the nymphs are able to detect changes in the structure of the xylem due to the trees
above which are deciduous, losing their leaves each autumn.
So they notice that the trees have dropped their leaves, the structure of the xylem will
change, and they count that as a year.
They do this pretty well.
They can count to 13 or 17 spot on.
So I find that really interesting that a little insect can count to 13 or 17.
I can't do simple math in my head, so pretty cool for a little bug.
It can count to 13, 17, ...sexy
So I think we're pretty much on board with what a cicada is.
Insect, six legs, three body parts.
They can fly when they're adult.
They live underground for 99% of their lives.
This particular species, group of species called Magicicada, what we're talking about,
only found in the northern, northeastern parts of North America.
Only found in the eastern parts of North America, I should say.
Once they have emerged, the adult life cycle or life stage is quite short, usually only
four to six weeks, and it's only for mating.
There's not much else purpose to this stage of the life.
It's easy to come up after being on the ground for 17 years, come up, make some noise, have
a giant orgy, die.
Sounds pretty fun.
Once they shed their exoskeleton and emerge as fully fledged winged adults, they are active
for about four to six weeks.
So after four to five days of the grand emergence of the brood, the males will begin singing
in choruses as the females wait nearby on trees.
The males alternate between singing and flying around until they find a suitable mate.
Both sexes will mate with several partners during the adult life stage.
The females can also lay up to 500 eggs and usually place the eggs in small slits of twigs
on trees or on the ground.
After this, the female will drop dead and then soon to be followed by the male, neither
living past early July.
The new nymphs will hatch and the journey underground as a collective new brood will
begin and they will emerge in either 13 to 17 years depending on the particular species
of this genus.
Okay, so let's get into the dark side of this beautiful emergence of life.
The fungal pathogen that has infected most of them and what it's going to do to them
because it's pretty gnarly on a scientific level.
It's quite cool, but also pretty fucked up.
Okay, so the upcoming super emergence...
Oh, I'm going to backtrack.
So this upcoming super emergence indicates that there was a very successful mating brood
emergence 17 years ago.
The brooding behavior exists mainly to overwhelm predators.
So this is a classic safety in numbers concept.
If the population is so large that even with predation occurring, the sheer number of individuals
means that many will reproduce before shortly dropping dead.
So safety in numbers, it's a good biological thing.
So now that we have a baseline understanding of what these deafening forest cuties are,
let's unpack the hypersexual pathogenic fungus.
Well, the villain of this story is an entomorpho-re-lean fungus, which in normal terms is a pathogen
of insects known as Massospora cicadina.
Sounds Spanish.
Massopora cicadina.
It is the only known pathogen that is synchronized to the cicadas life cycle.
So the mycosis or the fungal infection of the cicadas occurs in two stages.
So stage one is the infected cicadas who emerge as adults, produce haploid and conidio spores.
Cicadas will produce fungal spores of the pathogen to capable of infecting other actively
chorusing adult cicadas.
So all the adults have emerged, some of them are infected, they produce spores.
They can then hit another cicada, attach to another cicada, brush up against another
cicada and they will infect it.
The one adult cicada gets infected as another adult cicada, if that makes sense.
Stage two is later on and involves the same spores which then fall to the ground from
infected adult cicadas.
They then infect the newly born nymphs as they burrow underground through the soil and
then they emerge as infected adults in 13 to 17 years time.
Brutal, brutal life stage.
So you can be infected as an adult during the four to six weeks of your life and die
or you can be born and start your life journey and also get infected and then live for 13
to 17 years carefree as a nymph underground and then come up and die faster than usual
because something pretty bad happens to you if you're infected and I'll tell you right
now.
So what this infection does, so once the adults are infected the fungal spores will go into
their body, move down to their abdomen and erupt from their abdominal section causing
it to fall off.
So one third of their body which is usually quite large of the abdomen than the other
parts so half their body let's say falls off, it drops to the ground and with that their
genitals also fall off.
So the now breached abdomen will be exposed as the infecting fruiting body of spores I'll
say.
So basically the abdomen will fall off and it'll be replaced by a fruiting body of the
fungus which is made of spores, little tiny things, looks like little ribbons coming out
of it allowing for the dispersal.
So that's pretty gross but also pretty interesting that a higher section of the saccata can drop
off and it's still technically alive.
Let's unpack this a little bit more if you're still with me.
So the adults were observed studied by J.R.Cooley et al 2018 and were observed dragging their
fungal body, adults were observed dragging their fungal body leaving a trail of infectious
spores on trees behind them.
The clever little pathogen is also able to produce an amphetamine that increases the
sex drive of the cicadas making them extremely horny even though they are already extremely
horny because their entire purpose of life right now is to mate but they're becoming
hypersexual with this infection because it creates an amphetamine that increases their
sex drive making them extremely horny for all their brood counterpart.
Not only does it do this males infected with the disease will also observe changing their
behaviour.
So this is where it gets kind of cool and interesting because we're going to like how
a pathogen can literally change the chemistry and functioning of a particular species into
doing something completely different.
So this is the gay part that we were talking about.
So males were seen wing flicking in response to the calls of other males.
So this particular behaviour of wing flicking is only a behaviour that is done by sexually
receptive females which they do to attract a mate that they hear calling.
So they'll flick their wings to know that they're like I'm ready.
Males that are infected with Masosospora cicadina have been observed doing this so they're pretending
that they are females to get other males who are not infected to come over to them and
try to mate with them thus touching their exposed fungal booty and then infecting the
other male.
Fungal booty.
That's quite nice.
Gross.
So this means that they are tricking non-infected males like I just said to fly over and attempt
to mate with them thus becoming in contact with the fungal body of the deceptive male
and contracting the disease themselves.
This then doubles the number of cicadas that are infected individual comes in contact with
because not only is if it's a male cicada that's infected will try to mate with females
but they also are attracting males so they're getting with the whole population.
It is a queer party for everyone.
Unfortunately the fungal pathogen is running the show which is not nice.
So this is theorised to be caused by the pathogens manipulation of the victims endocrine or nervous
system.
That's pretty cool.
Like in The Last of Us if anyone's watched that where cordyceps another type of fungus
which does actually exist in insects is able to take over the host's body and control them.
So in ants if they get infected by the cordyceps fungus they will literally crawl up to a higher
point in the canopy or like plants or something to a vantage point latch on die and be stuck
there and then the pathogen the cordyceps will erupt from their head in a fruiting body
of spores.
I don't know what The Last of Us is based off if that was able to be transmitted to
humans.
So okay okay bear with me.
The Last of Us season 2 it's no longer cordyceps it's now massospora cicadina has taken over
and all remaining humans become infected with it and are running around having a giant orgy
but plot twist no one has any genitals because they've fallen off or any arses it's just
it's a nightmare that's what it is.
Gross.
Okay so these findings were not unique to Magicicada massospora.
These findings raise the possibility that the general phenomenon of zombie insects may
also include parasites that specifically hijack the host's sexual behaviors which is kind
of what's going on here.
So that's pretty cool it's pretty interesting.
So to summarize what we've learned today or what you might not have learned because you
probably zoned out long ago is that periodical cicadas emerge in North America and the eastern
parts this particular genus known as Magisicata is made up of seven species.
A cicada is an insect they have six legs three body parts and two wings in this case they
emerge every 13 to 17 years depending on the particular type of species.
They are called periodical because of this they spend 99 percent of their lives underground
as a nymph which is a juvenile form of an insect.
They feed on the xylem roots of deciduous trees above and they count the changes in
the xylem fluid when the leaves fall off the tree every year to know when to emerge.
They emerge in mass exodus as a brood they then attach themselves to a tree nearby and
molt their exoskeleton to reveal their beautiful winged bodies and they live for four to six
weeks and their main purpose is to mate and in this case this giant emergence most of
them are infected already with massospora cicadina.
So most of them are already infected with this and they emerge and once they have shed
the exoskeleton and are fully fledged adult the fungus then activates itself because it
knows what's going on and spreads throughout the body the abdomen drops off it pushes itself
out as a fruiting body when it spreads its spores around and then the giant orgy of cicadas
just becomes a hot pot for transmission of this pathogen and then the eggs that hatch
a few weeks later the nymphs crawl down through the grass into the soil to start their beautiful
life underground but most of them will encounter these microscopic spores on their way down
which have fallen from all the dead cicadas who have been infected above them and they
will become infected as a nymph and the pathogen will lie dormant for the entire duration of
its life cycle under there until it emerges as an adult and then quickly takes over and
replaces its abdomen and genitals.
So thank you for listening in and tuning into this episode this is my first full length
episode that I'm doing on the podcast so bear with me it will get better I promise it's
a passion project of mine that I just wanted to do it's really hard to do this so I'm learning
along the way so I'm sure there's lots of cringey moments or bits where you can hear
me lips smacking or sane arms or breathing really heavily so thank you for listening
the whole way through if you have I hope you found it interesting I have a lot more content
that I've gotten drafted up that I will be publishing soon so thank you I hope you enjoyed
this episode and as always remember this nature is gay so don't hide your DNA see ya.